The environmental engineering industry got its first taste of maturity in 1992, courtesy of the weak U.S. economy. Revenue growth, which had raced along at a 25%-30% clip for years, abruptly slowed by more than half, refuting claims that the environmental industry was recession-proof. According to an analysis of 200 engineering consulting firms by BTI Consulting Group, Boston, their average growth rate was 8% in 1991 and is estimated to be about the same in 1992. While no one is questioning the long-term health of the industry, most observers expect slower growth to continue even after the economy recovers. With more firms offering environmental services and customers growing ever more sophisticated and knowledgeable, environmental engineering firms will have to be better managed, more creative and more competitive about marketing themselves to gain, keep, and increase their share of the jobs available.